| 摘要 |
A component light source 200, e.g. for a display device, includes N LEDs 201-203, a photo-detector 240, and a collector 230, each LED having a light emitting chip in a package. Each LED emits light in a forward direction 221 and light in a side direction 222. The light generated in the forward direction is determined by a drive signal coupled to that LED. A portion of the light in the side direction leaves the package. The collector 230 is positioned such that a portion of the light in the side direction that leaves the package of each of the LEDs is directed onto the photo-detector 240. The photo-detector 240 generates N intensity signals, e.g. R, G, B signals, each intensity signal having an amplitude related to the intensity of the light emitted in the side direction by a corresponding one of the LEDs. The intensity signals are input to a feedback controller (310, fig 4) which, via interface circuits, controls drive signals to the LEDs. The collector 230 may be a circularly-symmetric reflector or a cylindrical reflector depending on the arrangement of the LEDs. |
